Answer:
It means the chemical entity is a radical
Explanation:
When we talk of unsaturation, we are referring to the number of pi-bonds in a chemical entity. The alkane, alkene and alkyne organic family are used to as common examples to explain the term unsaturation.
While alkynes have 3 bonds, it must be understood that they have 2 pi bonds only and as such their degree of saturation is two.
In the case of an alkene, there is only one single pi bond and as such the degree of unsaturation is 1.
Now in this case, we have a fractional 0.5 degree of unsaturation alongside the 3 to make a total of 3.5. So what’s the issue here?
The fractional part shows that the chemical entity we are dealing with here is a radical. While the integer 3 shows that there are 3 pi-bonds, the half pi bond remaining tells us that there is a missing electron on one of the atoms involved in the chemical bonding and as such, the 1/2 extra degree of unsaturation tends to tell us this.
Kindly recall that a radical is a chemical entity within which we have at the least an unpaired electron.
A second order reaction varies with the square of the concentration of the reactant. Therefore, halving the concentration will reduce the rate of reaction by a factor of 4.
The answer is E.
<span>I did some investigation and summarized the process and made a clearer explanation so those who are confused can imagine the process better :) A scientific theory attempts to explain and describe why things happen. Hypotheses are formed and experiments are done to validate or toss the hypothesis based on the data collected. The Atomic Theory has gone through lots of refining as a scientific theory. For instance, William Crookes conduced an experiment with cathode ray tubes powered by electricity that glowed when powered. Crookes placed an object in between the positive and negative electrode and concluded that the shadow made on the positive side was small particles of matter traveling from the negative side. But more evidence was needed so, later on, J.J. Thomson continued Crookes experiment. He tested what would happen if a negative or positive charged rod was placed along the ray tubes and if it would differ if a different element was used as the negative electrode. Thomson found out that the beam had negatively charged particles and that even if the negative electrode is substituted, the glow is still present, meaning that all elements also had the small negative particles. These particles(now known as electrons) were smaller than the atom and were added to the model of the atom dispersed throughout the neutrally charged atom inside its positive sphere. Now came along Rutherford hoping to support Thomsons model by firing positively charged particles at a thin gold foil thinking it would go straight through the foil, but instead it evenly distributed as they went through the foil, concluding that atoms have a small, dense nucleus(containing positive protons and most of the mass of the atom) that deflected the particles passing through. This was a drastic change in the model now knowing that 1 proton has 2000 times the mass of an electron, but its positive charge cancels the negative electron. After WW1, Chadwick and others were seeing that sometimes the mass of the atom was greater than the mass of the protons and the number of protons was less than the mass of the atom. So it was thought that there were extra electrons and protons adding mass in the nucleus but cancelling their charges, but Rutherford proposed a particle with mass but no charge and called it a neutron; made of paired protons and electrons. But scientists kept studying atoms since there was no evidence of the neutron. Chadwick repeated these experiments though, in hopes to find the neutron and succeeded in 1932, finding it in the nucleus with a close mass to the proton. Thanks to these experiments for refining a scientific theory, we now have a clearer model of the atom.</span>
<span>First, write the net ionic equation for the unbalanced reaction. If you are given a word equation to balance, you'll need to be able to identify strong electrolytes, weak electrolytes and insoluble compounds. Strong electrolytes completely dissociate into their ions in water. Examples of strong electrolytes are strong acids, strong bases, and soluble salts. Weak electrolytes yield very few ions in solution, so they are represented by their molecular formula (not written as ions). Water, weak acids, and weak bases are examples of weak electrolytes. The pH of a solution can cause them to dissociate, but in those situations, you'll be presented an ionic equation, not a word problem. Insoluble compounds do not dissociate into ions, so they are represented by the molecular formula. A table is provided to help you determine whether or not a chemical is soluble, but it's a good idea to memorize the solubility rules.
</span><span><span>arate the net ionic equation into the two half-reactions. This means identifying and separating the reaction into an oxidation half-reaction and a reduction half-reaction. </span><span>For one of the half-reactions, balance the atoms except for O and H. You want the same number of atoms of each element on each side of the equation. </span><span>Repeat this with the other half-reaction. </span><span>Add H2O to balance the O atoms. Add H+ to balance the H atoms. The atoms (mass) should balance out now. </span><span>Now balance charge. Add e- (electrons) to one side of each half-reaction to balance charge. You may need to multiply the electrons the the two half-reactions to get the charge to balance out. It's fine to change coefficients as long as you change them on both sides of the equation. </span><span>Now, add the two half-reactions together. Inspect the final equation to make sure it is balanced. Electrons on both sides of the ionic equation must cancel out. </span><span>Double-check your work! Make sure there are equal numbers of each type of atom on both sides of the equation. Make sure the overall charge is the same on both sides of the ionic equation. </span><span>If the reaction takes place in a basic solution, add an equal number of OH- as you have H+ ions. Do this for both sides of the equation and combine H+ and OH- ions to form H2O. </span><span>Be sure to indicate the state of each species. Indicate solid with (s), liquid for (l), gas with (g), and aqueous solution with (aq). </span><span>Remember, a balanced net ionic equation only describes chemical species that participate in the reaction. Drop additional substances from the equation.ExampleThe net ionic equation for the reaction you get mixing 1 M HCl and 1 M NaOH is:H+(aq) + OH-(aq) → H2O(l)Even though sodium and chlorine exist in the reaction, the Cl- and Na+ ions are not written in the net ionic equation because they don't participate in the reaction.</span></span>
Parasitism... basically a tick and a dog. The dog is the host, which is harmed by the tick.
